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The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Phototransformation in air

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
phototransformation in air
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
key study
Study period:
Not applicatble
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Qualifier:
no guideline required
Principles of method if other than guideline:
AOP calculation (Atkinson method)
GLP compliance:
no
Remarks:
not applicable
Light source:
other: not applicable
Reference substance:
no
Key result
DT50:
0.802 h
Test condition:
value is calculated based on average conditions (12 hours day and 1.5E6 OH radicals/cm3)
Remarks on result:
not measured/tested
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Transformation products:
not measured

- AOP Rate estimation: Overall OH Rate Constant = 160.0694 E-12 cm3/molecule-sec; Half-life = 0.067 days (12-hr day; 1.5E6 OH/cm3); Half-life = 0.802 Hrs

- Applicability domain: Hydrogen Abstraction, Reaction with N, S and -OH and Addition to Aromatic Rings

Validity criteria fulfilled:
not applicable
Conclusions:
Based on the results of the AOP, the estimated half-life (Atkinson method) of the test substance in the atmosphere (by hydroxyl radical oxidation) is 0.802 hours.
Executive summary:

The half-life of the substance following reaction in the atmosphere with hydroxyl radicals was estimated using the Atkinson method in Atmospheric Oxidation Program version 1.8. Based on 1.5E6 OH radicals/cm3 and 12-hr per day, the overall OH rate constant was estimated to be 160.0694E-12 cm3/molecule-sec, with a 0.067 days half-life (equivalent to 0.802 hours). Based on the findings, the exposure to air can be considered to be negligible.

Description of key information

Estimated photodegradation half - life (Atkinson method) = 0.802 hours, in the atmosphere by hydroxyl radical oxidation, Hayes 1998

Key value for chemical safety assessment

Half-life in air:
0.802 h
Degradation rate constant with OH radicals:
0 cm³ molecule-1 s-1

Additional information

Phototransformation in air

The half-life of the substance following reaction in the atmosphere with hydroxyl radicals was estimated using the Atkinson method in Atmospheric Oxidation Program version 1.8. Based on 1.5E6 OH radicals/cm3 and 12-hr per day, the overall OH rate constant was estimated to be 160.0694E-12 cm3/molecule-sec, with a 0.067 days half-life (equivalent to 0.802 hours). Based on the findings, the exposure to air can be considered to be negligible.

Volatilisation

Additional volatilisation properties of the test substance in formulation were investigated in another study (Maclver, 1996; not included in the current submission) showing 21.9% and 34.4% volatilisation from air and leaf, respectively, after 24h (20°C, air stream of 1m/s).